Vessel-carried level-luffing crane



May 21, 1963 P. c. VERTREES ETAL ,090,

VESSEL-CARRIED LEVEL-LUFFING CRANE Filed April 6, 1961 4 Sheets-Sheet l INVENTORS 'PHUL C. VFRTREE'S ATTORNEYS May 21, 1963 P. c. VERTREES ETAL 3,090,496

VESSEL-CARRIED LEVEL-LUFFING CRANE 4 Sheets-Sheet 2 Filed April 6, 1961 ATTORNEYS May 21, 1963 P. c. VERTREES ETAL 3,090,496

VESSEL-CARRIED LEVEL-LUFFING CRANE Filed April 6, 1961 FIG.5

FIG.3

y 1963 P. c. VERTREES ETAL 6 VESSEL-CARRIED LEVEL-LUFFING CRANE Filed April 6, 1961 4 Sheets-Sheet 4 JNVENTORS: P/YUL c. VERTR rEs cums G. H/KKEA/B ERGER @LLMM ATTORNEYS bearings which support the latter.

United States Patent 3,090,496 VESSEL-CARRIED LEVEL-LUFFHJG CRANE Paul C. Vertrees and Claus G. Hackenberger, Tacoma, Wash., assignors to Tacoma Boathuilding Co., Inc, Tacoma, Wash., a corporation of Washington Filed Apr. 6, 1961, Ser. No. 101,267 18 Claims. (Cl. 212-35) This invention relates to level-lufling cranes, and particularly one which adapts itself to use on shipboard as a part of a vessels permanent deck gear. The crane of the present invention, while it is in no sense limited to any specific usage, peculiarly adapts itself to employment on a mine-sweeping vessel for moving floats or the like from positions upon the deck to and from water-borne positions alongside or to the stern of the vessel.

As one of its objects the invention purposes to provide a crane of the level-lumng type which provides an unusually deep throat when in its luffed or fully retracted position, thus to accommodate the crane to the extended tails of the rather elongated floats which are commonly employed in mine-sweeping work.

The invention has the further and important object of providing a level-lufiing crane for shipboard usage which requires minimum space for its mounting upon the vessels deck and exposes little more than the cranes boom arm and luffing links therefor above such deck, giving these working parts a secure mounting by means of a king post deriving its support wholly from below-deck bearings.

As a further object still the invention aims to provide a level-luiiing crane for shipboard usage characterized in that its loading line is carried through a hollow center of the king post to a below-decks winch.

A yet further object of the invention is to provide a level-lufiing crane in which all of the operations performed, namely hoisting, sluing, and luffing, are hydraulically powered.

A yet further and important object is to provide a hydraulically powered level-lufling crane embodying within its hydraulic system a means separate and apart from the systems control valve establishing a positive hydraulic lock holding the cranes boom against any tendency to creep toward the reach position.

Still additional objects and advantages in view looking to the provision of a perfected level-luffing crane particularly designed for the specific purpose of handling waterborne mine-sweeping equipment more efliciently than has been heretofore possible will, with the foregoing, appear and be understood in the course of the following description and claims, the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

FIGURE 1 is a perspective view illustrating the abovedecks portion of a level-lufiing crane constructed in accordance with the preferred embodiment of the present invention, and shown supporting a float of a type commonly used in mine-sweeping operations.

FIGURE 2 is a side elevational view of the crane, including the below-decks portion thereof but deleting the Dash-and-dot lines in this view show the outline of a vessel on which the crane is mounted.

FIG. 3 is a front elevational view of the crane, with the below-decks flexible hoses which feed hydraulic fluid to and from the cranes luffing cylinder shown fragmentarily.

FIG. 4 is a fragmentary enlarged-scale side elevational view of the crane.

FIGS. 5 and 6 are fragmentary longitudinal vertical sectional views drawn to a yet larger scale to detail upper and lower bearings which support the crane.

FIG. 7 is a schematic horizontal sectional view drawn to an enlarged scale on line 77 of FIG. 3 to indicate the degree of swing or sluing travel to which the crane admits.

FIG. 8 is a fragmentary longitudinal vertical sectional view employing the same scale as that of FIG. 4 and detailing the manner in which chain connectors, used to releasably couple one to another length of cable, traverse sheaves over which the hoist cable is trained. The sheaves here shown are those portrayed in FIG. 4.

FIG. 9 is a schematic view illustrating the lufling portion of the cranes hydraulic system and augmenting same by portraying symbolically and to an enlarged scale a valve circled in said schematic disclosure.

Referring to said drawings the numeral 10 designates a hollow king post which extends through the deck 11 of the vessel, deriving support from upper and lower bearing assemblies. As shown in FIG. 5, a journal bushing 12 produces the upper of these bearings and has its bearing ring 13 secured to the underside of said deck. A thrustand-journal bearing 14 (FIG. 6) provides the lower support and has its ring 15 rigidly secured to a below-deck framework 16. A split ring 17 holds the king post against rising.

The hollow center of the king post is adapted to accommodate a hoist line 20 running from the above-deck working portion of the crane to the winding drum 21 of a hydraulically driven below-deck winch 22. Between the winding drum and a bottom opening of the king post into which the line runs, said line is trained over an idler sheave 23. A bull gear 24 is rigidly secured in surrounding relation to the king post between said bearings 13 and 14,

and a below-deck reversing hydraulic motor 25 drives a pinion 26 in mesh with the bull gear for imparting turning movements to the latter.

of an A-fr-ame when viewed from the front.

Designated by 32, the link which is pivoted to the upper cross-pin 30 has its wrist connection 33 with'the cranes jib or boom 34 located at the extreme rear end of the latter, thus functioning as the aft lufiing link. As is usual with level-lufling cranes the wrist pin 35 which pivotally connects the other or forward luffin-g link 36 to such boom 34 is spaced to the front of said wrist pin 33. When the pantograph assembly which said boom, the two links, and the head of the king post produce is so located that the links lie perpendicular to the deck, the forward wrist pin 35 occupies a horizontal plane spaced above the horizontal plane occu pied by the after wrist pin 33 a vertical distance moderately less than the vertical distance to which the root pivot 31 is spaced below the root pivot 30. This relationship, taken in conjunction with a dimensioning and spacing of the lufiing links substantially as shown maintains the free end of the boom very nearly level throughout its luffing travel. Sheaves 39, 37 and 38 to accommodate the hoist line 20 are journal-mounted on the boom for rotation about a terminal pin '40 and the wrist pins 35 and 33 respectively. Said hoist line in its travel downwardly from said sheave 38 through the hollow center of the king post to the sheave 23 passes first about a sheave 41 j ournaled to rotate about the center of the root pivot 30 as an axis and then jogs inwardly and over ano e-9e leasablycouples one to another length of the hoisting cable 20. As detailed in FIG. 8, it will be seen that the smaller link 47 engages the eye 48 of one cable socket 50 while the larger link 46 engages a shackle 51 which in turn releasably engages the eye 52 of a complementing cable socket 53. It can be here pointed out that the connecting lengths of cable 20 are fitted at the outer end with a hook which releasably engages either a fioat 49 or the inhaul pendant (not shown) of an acoustic device which in use is customarily suspended from the float. While not illustrated, a tripping line for the hook may mnwthrough a block carriedby an eye provided at the outer end of the boom 34.

For the lufiing operation of the crane there is provided a rod 54 driven by a piston Working in a doubleacting hydraulic jack cylinder 55, the cylinder being mounted by trunnion pins 56 between cheek block 57 rigid with the head of the king post. Extending longitudinally ofr-the crane in an approximately horizontal position, the piston rod 54 has its exposed end pivotally attached as "at 58 to the aft luthng link at a point spaced above the root pivot-30.

Pipes and hoses through which hydraulic fluid under pressure is delivered from a below-deck point selectively to either of the two ends of the cylinder, while returning fluid from the other end to a below-deck reservoir, extend along the sides of the king post. In compensation of the rotation of the king post as the latter turns to give sluing movements of the crane, both the line 60 which feeds to and from the after end of the cylinder and the line 61 which feeds to and from the forward end of the cylinder include, belowdeok-s, a respective flexible hose 62 and 63 running between sets of hydraulic swivels 64-65 and 6667. These swivels are or may be like or similar to the swivel illustrated and described in pending application for Letters Patent of the United States filed June 15, 1960, Ser. No. 36,284. One swivel of each set is fixed to the king post and the other upon a stationary control mount. As can be seen from an inspection of FIGSJ4 and 9 a sequence or counterbalance valve 70 is provided between the hydraulic line 61 and the forward end of the jack cylinder, connecting with the latter by a pipe 71 and also connecting by a pilot line 72 with the hydraulic line 60. This sequence valve has a free flow by pipes 61 and 71 directively from the pressure source (not shown) to the cylinder but permits flow in the reverse direction only when the pressure within the pilot line 72 closely approaches the pressure which obtains in said pressure source. The sequence valve thus performs the iunction .of a hydraulic lock by precluding seepage of oil from the forward end of the jack cylinder during periods when the boom is immobile at any position between its two extremes of reciprocal motion. Operation of the responsible control valve so as to charge hydraulic fluid from the pressure source into the hydraulic line 60 perforce acts through the pilot line to open the sequence valve and permit eduction of hydraulic fluid from the forward end of the cylinder. It is apparent that the only creeping influence to which the boom is subject is one which tends to move the boom toward its reaching position. There is thus no need to employ more than the single sequence valve in the l-ufling circuit in that installation of a similar valve within the hydraulic line 60 would serve no useful end.

While not illustrated each of the two hydraulic lines which connect with the two parts for the crane-sluing reversible hydraulic motor 25 includes a counterbalance valve functionally identical with the counterbalance valve 70. The pilot line in'the instance of each such counterbalance valve connects with the hydraulic line related to the other side of the motor, thus locking the motor against rotation in either direction unless fluid from the pressure source is charged to one or the other side of the reversing motor. It will perforce be understood that the direction in which both of said counterbalance valves are free-opening is toward the reversing mo tor 25. There is also provided for the crane a locking pin 78 for use against mine shock and which is insertable from an above-deck position through registering openings provided in fittings 75 and 76 secured to the king post and the deck plate, respectively. A locking pin (not shown) is also provided for positively holding the crane in a :fully retracted position, this pin being in sertable horizontally through registering openings provided in lugs 73- and 74 rigid with the forward luffing link and the post head, respectively.

It is believed that the manner of operation of the crane 'will have been clearly. understood from the foregoing detailed description of our now-preferred illustrated embodiment of the invention. Changes in the details of construction can be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.

What we claim is:

l. A ship-carried level-luffing crane comprising, in combination with a sea-going ship, a mount exposed above the deck of the ship and journaled therefrom for rotation about a vertical axis, a boom arm, forward and aft upright links pivoted at their lower ends to the mount and at their upper ends to an end portion of the boom, said links being dimensioned and placed so that swing movement of thelin'ks about said mount pivots as an axis imparts level-lufiing travel to the free end of the boom, a hoist line, sheaves on the boom arm guiding said hoist line, power means located above deck for 1nding the boom ar-m, andpower means located below deck for operating said hoist line and for turning the mount so asto slue the crane.

means for luffing the boom arm includes a hydraulically operated double-acting jack cylinder engaging one of said links and taking a purchase from the mount.

4. Structure according to claim 3 having within the hydraulic line which is responsible for moving the boom to the retracted extreme of its lufiing travel a sequence valve which permits hydraulic fluid to be supplied freely to the cylinder while normally closing the line against return of said fluid to the source, said sequence valve being opened automatically upon the development of a predetermined pressure in the hydraulic line which is responsible for moving the boom to the other or extended extreme of its lufling travel.

5. A ship-carried level-lufling crane comprising, in combination with a sea-going ship having an opening in its deck, a king post received through said opening so that a bottom portion of the post lies below and a head portion is exposed above the deck, bearings engaging said bottom portion of the king post to provide a thrust mounting and upper and lower journal mountings therefor engaging said bottom portion of the king post, a boom arm, forward and aft upright links pivoted to said exposed head portion of the king post and supporting said boom arm for levellufiing travel, means for powering the boom arm in its lufiingtravel, a hoist line, sheaves on the boom arm guiding said hoist line, power means for operating said hoist line, and power means for turning the king post so as to impart sluing movements to the crane.

6. A ship-carried level-lufling crane comprising, in combination with a sea-going ship, a mounting head rising above the deck of the ship, bearings providing both thrust and journal mountings for said mounting head, a boom arm, forward and aft upright lufiing links pivoted by lower ends to said mounting head and by upper ends to the rear end portion of the boom giving support to said boom for level-lufiing travel thereof, said links generally paralleling one another and having a swing travel moving their upper ends approximately equal distances fore and aft of a perpendicular raised from the respective root pivot, a hoist line for the boom, sheaves guiding said hoist line, and power means for operating said hoist line, for swinging the links to luff the boom arm, and for turning the head so as to slue the crane, the aft luffing link being shorter than the forward lufiing link, said lufling links, the rear end portion of the boom, and the' mounting head producing a pantograph assembly characterized in that, when located at the center of said swing travel, the aft links upper and lower pivots lie the former below and the latter above the corresponding pivots of the forward link.

7. A shipcarried level-lufiing crane comprising, in combination with a sea-going ship having an opening in its deck, a hollow king post received through said opening so that a bottom portion of the post lies below and a head portion is exposed above the deck, bearings providing both thrust and journal mountings for said king post, a boom arm, forward and aft upright lufiing links pivoted by lower ends to said exposed head portion of the king post and by upper ends to the rear end portion of the boom giving support to said boom for level-lufling travel thereof, said links generally paralleling one another and having a swing travel moving their upper ends approximately equal distances tore and aft of a perpendicular raised from the respective root pivot, a below-decks winch, a hoist line running from said winch through the hollow center of the king post to guide sheaves provided upon said head portion of the king post and the boom, and power means for operating said hoist line, for swinging the links to luff the boom arm, and for turning the king post so as to slue the crane, the aft lufiing link being shorter than the forward lufling link, said lufiing links, the rear end portion of the boom, and the mounting head producing a pantograph assembly characterized in that, when located at the center of said swing travel, the aft links upper and lower pivots lie the former below and the latter above the corresponding pivots of the forward link.

8. A ship-carried level-luffing crane comprising, in combination with a sea-going ship, a mount exposed above the deck of the ship and journaled therefrom for rotation about a vertical axis, a boom arm, forward and aft upright links pivoted at their lower ends to the mount and at their upper ends to an end portion of the boom, said links generally paralleling one another and being so dimensioned and placed that the upper ends have a swing travel moving approximately equal distances fore and aft of a perpendicular raised from the respective root pivot while holding the boom in substantially a single horizontal plane, a hoist line for the boom, sheaves guiding said hoist line, and power means for swinging the links so as to luff the boom arm and for turning the mount so as to slue the crane.

9. Structure according to claim 8, one of said guide sheaves being journaled from the mount for rotation about an axis coinciding with the root axis of the aft lufiing link.

10. A ship-carried level-luffing crane comprising, in combination with a sea-going ship having an opening in its deck, a king post received through said opening so that a bottom portion of the post lies below and a head portion is exposed above the deck, below-decks bearings providing both thrust and journal mountings for said king post, a boom arm, forward and afit upright lufling links pivoted by lower ends to said exposed head portion of the king post and by upper ends' to the rear end portion of the boom giving support to said boom for level-lufling travel thereof, said links generally paralleling one another and'having a swing travel moving their upper ends approximately equal distances fore and aft of a perpendicular raised from the respective root pivot, a hoist line for the boom, sheaves guiding said hoist line, and power means for operating said hoist line, for swing-ing the links to luff the boom arm, and for turning the king post so as to slue the crane, the power means for turning the king post being located below-decks and comprising a pinion meshing a bull gear fixed to the post and driven from a reversing hydraulic motor.

11. A ship-carried level-lufling crane comprising, in combination with a sea-going ship having an opening in its deck, a hollow king post received through said opening so that a bottom portion of the post lies below and a head portion is exposed above the deck, below-decks bearings providing both thrust and journal mountings for said king post, a boom arm, forward and aft upright lufiing links pivoted by lower ends to said exposed head port-ion of the king post and by upper ends to the rear end portion of the boom giving support to said boom for level-luffing travel thereof, said links generally paralleling one another and having a swing travel moving their upper ends approximately equal distances fore and aft of a perpendicular raised from the respective root pivot, a hoist line for the boom, sheaves guiding said hoist line, and power means for operating said hoist line, for swinging the links to lutf the boom arm, and for turning the king post so as to slue the crane, the power means for turning the king post being located below-decks and comprising a pinion meshing a bull gear fixed to the post and driven from a reversing hydraulic motor, two of said guide sheaves being journaled one from the boom and the other from the head portion of the king post for rotation about axes coinciding, respectively, with the upper and the lower pivot axis of the aft lufiing link, said hoist line running over said two sheaves and thence downwardly through the hollow center of the king post to a below-decks winch.

12. Structure according to claim 11 in which the power means for lutfing the crane comprises a doubleacting hydraulic jack cylinder trunnion-mounted from the exposed head of the king post for rocker movement about an axis paralleling and spaced from the root axis of one of said lufling links and having the rod of its piston pivotally connected to said link at a point spaced from such root axis.

13. The crane recited in claim 12 in which fluid for the operation of said piston is fed to and from said cylinder by lines which extend downwardly along said king post to hydraulic swivels which are secured to the post below the deck of the ship and connect by flexible hoses with hydraulic swivels secured to the ship.

14. The crane recited in claim 12 in which the line through which hydraulic fluid is fed to the end of the cylinder responsive for moving the boom to the retracted extreme of its lufiing travel is fitted with a sequence valve which normally closed said line against return flow of fluid while permitting free-flow to the cylinder, said sequence valve being opened automatically upon the delivery of hydraulic fluid to the other end of the cylinder.

15. The crane recited in claim 11, a water-tight seal being provided at the deck line between the king post and the opening in the deck through which the king post is received.

16. The crane recited in claim 11, the hoist line having a release coupling within its length including two connecting chain links, the guide sheaves presenting a 3,090,496 7 8 Wide groove for the hoist lineand having a narrow central :the same at the retracted extreme of its swing travel and 1 groove recessed below the hoist-line groove and within for holding the king post against rotation.

whichone of said coupling links tracks as the coupling the sheave References Cited in the tile of this patent 17..The crane recited in claim 11, the below-decks 5 UNITED STATES PATENTS journal mountings for the king post comprising vertically 2,787,383 Amos et APR 2, 1957 'spaced hearings one located above and one located below 7 the bull gean FOREIGN PATENTS 18. The crane recited in claim 11, releasable means 640,558 France Apr. 2, 1928 being provided for positively locking the boom to locate 10 1,172,981 France Oct. 20, 1958 

1. A SHIP-CARRIED LEVEL-LUFFING CRANE COMPRISING, IN COMBINATION WITH A SEA-GOING SHIP, A MOUNT EXPOSED ABOVE THE DECK OF THE SHIP AND JOURNALED THEREFROM FOR ROTATION ABOUT A VERTICAL AXIS, A BOOM ARM, FORWARD AND AFT UPRIGHT LINKS PIVOTED AT THEIR LOWER ENDS TO THE MOUNT AND AT THEIR UPPER ENDS TO AN END PORTION OF THE BOOM, SAID LINKS BEING DIMENSIONED AND PLACED SO THAT SWING MOVEMENT OF THE LINKS ABOUT SAID MOUNT PIVOTS AS AN AXIS IMPARTS LEVEL-LUFFING TRAVEL TO THE FREE END OF THE BOOM, A HOIST LINE, SHEAVES ON THE BOOM ARM GUIDING SAID HOIST LINE, POWER MEANS LOCATED ABOVE DECK FOR LUFFING THE BOOM ARM, AND POWER MEANS LOCATED BELOW DECK FOR OPERATING SAID HOIST LINE AND FOR TURNING THE MOUNT SO AS TO SLUE THE CRANE. 